1. Field of the Invention
The present invention relates to adaptive cruise speed controlling apparatus and method for an automotive vehicle to follow a preceding vehicle, the preceding vehicle running ahead of the vehicle on the same traffic lane, while maintaining a target inter-vehicle distance between the vehicle itself (also called, a host vehicle) and the preceding vehicle.
2. Description of the Related Art
A Japanese Patent Application First Publication No. Heisei 11-20503 published on Jan. 26, 1999 exemplifies a previously proposed adaptive cruise speed controlling apparatus.
In the above-described Japanese Patent Application Publication, a first gain is multiplied with a difference between an actual inter-vehicle distance from the host vehicle to the preceding vehicle and the target inter-vehicle distance. The multiplied difference is added to a relative velocity of the preceding vehicle to the host vehicle which is multiplied with a second gain. The added value provides a term of a setting of a target vehicular velocity. A regulator such as to control the braking or driving force of the host vehicle so that the vehicular velocity of the host vehicle is made coincident with the target vehicular velocity is used to make the host vehicle follow the preceding vehicle.